If you've been to Africa but haven't visited Victoria Falls then you should. The falls are visible from two countries: Zambia and Zimbabwe. A bridge connects the two and it is possible to cross from one to the other to see the falls from both sides but take stock of the visa situation first.
In Zambia admission costs $20 and the site is easily accesible by blue minibus from Livingstone (bus park just down the road from Shop Rite supermarket).
Security on site is good and visible, though not so much as to intrude, and so you can pretty much wonder as you wish and not keep looking over you shoulder.
Wading/padlling is possible at the top of the falls and there even some islands you can cross to (depending on recent rainfall, of course). A security man on site will direct you.
The Boiling Pot is a great spot for a picnic and a rest. Its virtually at the foot of the falls in a chasm which makes for a lot of roar and amazing sights including adrenalin junkies bungee jumping from the bridge (no doubt you'll be approached at some stage by a tout offering you the same priviledge for a fee).
You reach the pool through a small area of rainforest which is quite picturesque. The way is well-marked and passes over several streams.
You can pick up gifts and local handicrafts - some of them actually quite good - from the stalls at the entrance to the park. Refreshments are also available though, if you're using public transport, I recommend grabbing a cold beer from one of the vendors at the bus park which is about 10 minutes away on the other side of the road, and drinking it in local company under the shade of the acacias.